/// <summary>
/// Reads the key/value and updates the database with the relevant value
/// </summary>
private void HandleKeyspaceEvent(DatabaseInstanceData dbData, string key, string value)
{
if (value == "expired")
{
//A key has expired. Sometimes the expiry is performed in-memory, so the key may have already been removed.
//It's also possible that the expiry is performed in redis and not in memory, so we listen for this event.
dbData.MemoryCache.Remove(new[] { key });
}
}
private void HandleKeyspaceDetailEvent(DatabaseInstanceData dbData, string key, string machine, string eventType)
{
var keySpaceDetails = new Dictionary <string, string>();
keySpaceDetails.Add("Machine", machine);
keySpaceDetails.Add("key", key);
keySpaceDetails.Add("Event", eventType);
string eventName = eventType.Split(':').First();
string eventArg = "";
if (eventName.Length < eventType.Length)
{
eventArg = eventType.Substring(eventName.Length + 1);
}
if (eventName == "hset" || eventName == "hdel" ||
eventName == "hincr" || eventName == "hincrbyfloat" ||
eventName == "hdecr" || eventName == "hdecrbyfloat")
{
//eventArg is the hash entry name. Since it has changed, remove it.
dbData.MemoryHashes.Delete(key, new[] { (RedisValue)eventArg });
}
else if (eventName == "srem")
{
//Removing an item from a set.
dbData.MemorySets.RemoveByHashCode(key, new[] { eventArg });
}
else if (eventName == "zadd")
{
//An item is added to a sorted set. We should remove it from its current location if it's already there.
int hashCode;
if (int.TryParse(eventArg, out hashCode))
{
dbData.MemorySortedSets.RemoveByHashCode(key, hashCode);
}
}
else if (eventName == "zrem" || eventName == "zincr" || eventName == "zdecr")
{
//An item is removed from a sorted set.
int hashCode;
if (int.TryParse(eventArg, out hashCode))
{
dbData.MemorySortedSets.RemoveByHashCode(key, hashCode);
}
}
else if (eventName == "zremrangebyscore")
{
if (!string.IsNullOrEmpty(eventArg))
{
string[] scores = eventArg.Split('-');
if (scores.Length == 3)
{
double start, stop;
int exclude;
if (double.TryParse(scores[0], out start) && double.TryParse(scores[1], out stop) && int.TryParse(scores[2], out exclude))
{
dbData.MemorySortedSets.DeleteByScore(key, start, stop, (Exclude)exclude);
}
}
}
}
else if (eventName == "del")
{
//A key was removed
dbData.MemoryCache.Remove(new[] { key });
}
else if (eventName == "expire")
{
//The TTL has changed - clear it in memory
dbData.MemoryCache.ClearTimeToLive(key);
}
else if (eventName == "rename_key")
{
//the arg contains the new key
if (!string.IsNullOrEmpty(eventArg))
{
dbData.MemoryCache.RenameKey(key, eventArg);
}
}
else if (eventName == "set" /* Setting a string */)
{
//A key has been set by another client. If it exists in memory, it is probably now outdated.
dbData.MemoryCache.Remove(new[] { key });
}
else if (eventName == "setbit" || eventName == "setrange" ||
eventName == "incrby" || eventName == "incrbyfloat" ||
eventName == "decrby" || eventName == "decrbyfloat" ||
eventName == "append")
{
//Many string operations are not performed in-memory, so the key needs to be invalidated and we go back to redis for the result.
dbData.MemoryCache.Remove(new[] { key });
}
else if (eventName == "zremrangebyrank" || eventName == "zremrangebylex")
{
//Many sorted set operations are not performed in-memory, so the key needs to be invalidated and we go back to redis for the result.
dbData.MemoryCache.Remove(new[] { key });
}
}
internal void HandleKeyspaceEvents(DatabaseInstanceData dbData)
{
_databases.Add(dbData);
}